Electric switch-board



(No Model.)

T. J. PERRIN.

ELECTRIC SWITCH BOARD.

No. 271,913. Patented Feb.6,1883.

Illllllllll n ur xmuull A (l llmlllllull lll un l mmdmummlll l a I l a l l l l x 1 1 l x l l 25 2' zia 2z i z'o 19 18 17* 16 1'5 14 THOMAS J. PERRIN, OF BROOKLYN, NEW YORK.

ELECTRIC SWITCH-BOARD.

SPECIFICATION forming part of Letters Patent No. 271,913, dated February G, 1888.

Application led September 20, 1882.

To all whom tt may concern:

Be it known that I, THOMAS J. PERRIN, a citizen of the United States, and a resident of Brooklyn, in the county ofKings and State of New York, have invented certain new and uscful Improvements in Electric Switch-Boards,

of which the following is a specication.

My invention relates to certain improvements in the constructionotI switch boards such as are commonly employed at the central oices of telegraph and telephone exchange systems for placing in electrical connection the terminals of any two normally-independent conductors or subscriber-lines, or for connecting them with an apparatus at the central office for receiving and transmitting signals or communications.

Among the various methods heretofore employed for connecting the terminals of the conductors constituting the subscriber-lines., the two which have proved to be the most etticient in practice are, first, that in which each subscriber-line is provided with a metallic terminal plate, which respective plates may be placed in electrical connection, in any desired combination, by means of movable connectors formed of switch -plugs electrically united with each other by flexible conductingcords 5 and, second, that in which each subscriber-line terminal is provided with two conducting-strips or series of contact-plates, cach intersecting the plane of one of the conducting-strips or series of contact-plates of each ot' the remaining terminals, at which intersecting points a movable connector is applied as required. The principal inconvenience experienced in the use ofthe contact-plates and conducting-cords arises from the liability of the cords to become entangled with each other when several subscribers are to be coupled with each other, and to be broken by the continual bending to which they are subject. This construction, moreover, necessitates the handling of two switch-plugs, one being inserted in the contact-plate of each subscriberline. The second method, while it dispenses.

(No model.)

ion of an intersecting point for the terminals, whereby any one line may be placed in connection with any other by means of a single connector or switchplug, involves the employment of two contact-strips for each subscriber-line terminal. These strips are placed at right angles with each other, and each terminal has therefore two distinct contactpoints at which itmay be connected with any other terminal.

The object ot' my invention is to organize a.

minal conductor or strip for each subscriberline, the conductors or strips being arranged in consecutive order, corresponding to the designating-numerals of the subscriber-lines, and in providing each longitudinal terminal conductor with a series ol contact-plates, one corresponding to and connected by transverse conductors with each numerically-succeeding longitudinal conductor, the contact-plates corresponding to the numerically-preceding longitudinal conductors being dispensed with. The reason for making use of this organization will be evident when it is considered that any given terminal may be connected with any succeeding terminal by means of a movable connector inserted between itself and the contact-plate corresponding to and transversely connected with the said succeeding terminal, and that the given terminal may be connected with anypreceding terminal by means of a connector inserted between the said preceding terminal and the contact-plate corresponding to the given terminal.

The invention also consists in arranging the contact-plates in a convenient manner upon either side ofthe longitudinal terminals or contact-strips, and in certain details of construction hereinafter specitically set forth.

In the accompanying drawing, which illus- IOO 2 armoire.

trates my invention, l have shown a front elevation of a switch-board embodying the several features of my invention, and showing in diagram its circuit-connections.

Referring to the drawing, A represents a suitable frame or board for supporting the various devices constituting` the switch-board. The numerals l to 25, inclusive, represent a 4series ot' subscriber-lines, twenty-tive in number, respectively connected with corresponding bars or strips of metal, (numbered a a2 a, &c.,) which constitute longitudinal terminal conductors for the respective subscriber-lines. The conducting terminals a a2 a3, the., are preferably arranged vertically and in numerical order upon the board A, beginning at the left side and increasing numerically toward the right to the number 13, While at the same time they successively decrease in length toward the righ t. The fourteenth strip is placed beneath the thirteenth, and the numericallysucceeding strips are placed at the lower portion of the board, increasing numerically and decreasing in length toward the left, thus lilling up the triangular space lett vacant by the strips of decreasing length upon the upper portion ot' the board. rlhus the strip numbered a comes beneath the strip a, and am beneath the strip a, as illustrated with reference to the conductors 12 and 20 by the dotted lines M. The rst terminal conductor numbered 1 is provided upon either side with ccntact-plates b, one corresponding to and connected with each succeeding strip. rlhe con tact-plates b are numbered from 2 to 25, inclusive, the even numerals being preferably arranged upon the left of the strip a' and the odd numerals upon the right. Each contactplate b2 b3 b4, 85e., is electrically connected by a transverse branch conductor beneath the board with that longitudinal conductora which is designated by a corresponding numeral, as illustrated with reference to the conductors 12 and 20 by the dotted lines M. Suitable apertures, c, are formed along the Whole length of the longitudinal conductors upon each-side, opposite the contact-plates Z1, for allowing the insertion ofsnitable Wedge-shaped switch-pins, d, which constitute movable connectors and serve to place any conducting-strip in electrical connection with any desired adjacent contact-plate, and thus with its corresponding longitudinal conductor. 1`he contact-plates upon the right ofthe terminal a serve also for making connections upon their opposite sides With the secondterminal, a2, and another series 'of contact-plates, b4 l)6 128, Ste., corresponding with the numerically-succeeding terminals which are designated by the even numerals, is arranged upon the right of the terminal a2. In the like manner each terminal a a a, duc., is provided upon one side with contact-plates corresponding to and transversely connected with the terminals designated by the uneven numerals greater than its oWn,and upon the other side with contactplates ot' the same character designated by the even numerals.

At the outer end of each terminal or conducting-strip a a2 a3, the., is provided a contact-plate, c. Each of these contact-plates is transversely connected by a wire, w, in which is preferably included an annunciator device or visual signal, H, with a conductor, G, extending to the earth at E. rllhe annunciator devices H, one of which is provided for each subscriber-line, may be of any suitable or wellknown construction, adapted to be actuated by a current from the subscriber-line traversing the corresponding earth-circuit to exhibit a designating visual signal corresponding to that line. The devices which I prefer to eniploy consist of an electro-magnet provided with means for releasing a drop, 7i, and exhibiting a numeral corresponding to that employed for designating the corresponding subscriber-line. rlhis apparatus is well known, and forms no part of my invention. A movable connector or switch-pin, d, is normally placed in one ofthe apertures c ot' each terminal strip a, opposite the adjacentcontact-plate c, thereby placing' each subscriber-line in electrical connection with the earth through its corresponding annunciator. A second series ot'contact-plates,f, is likewise provided, one heilig placed at the outer extremity of each conducting-strip a.. The platesfare placed in electrical connection, by atransverse wire, w', With any suitable signal-transmitting device, K, thence by the Wires to2 and w3 through suitable transmitting and receiving apparatus, as shown at R and R', with the earth at E. battery, 0, one pole ofwhichis connected with the earth at E and the other pole with the working-contact ot' the transmitting device K, may be used for transmitting electrical impulses as desired upon the conductor G', and thus through any terminal conducting-strip a, by Way ot' the corresponding contact-plate, f, when thc two are connected by a connector, d, and thus to the corresponding subscriber-line. have shown also a local battery, o, Which is employed in connection with the transmitting device 1t in a manner Well understood.

The operation of the device is as follows: Each subscriber-line 1 2 3, &c., is normally kept in electrical connection, through the corr sponding longitudinal terminal a, With one of the contact-plates c by means of the connectors or switch pins d, which electrically unite the same, and thus, by means ofthe conductors w and G, directly with the earth at E. An y individual subscriber' desiring to bcplaced in communication with another signals to the central otlice by closing the electric circuit through hissubscriber-lineu Thusifsubscriber No. 6, for exam ple, desires to be connected with subscriber No. l2, he closes his circuit through the subscriber-line 6, the current thereupon traversing the terminal c6, connector d, contactplate c, Wirew, the annunciator device H6 to the conductor G, and thus reaching the earth at E.

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The annunciator-drop, being released by the action of this current, exhibits the numeral 6. The attendant at the central station thereupon transfers the movable connector als, adjacent to the conducting-strip a6, to the aperture c, adj acent to the contact-plate f, thereby connecting the subscriber-line 6 with the yearth at E by a route which includes the transmitting and receiving devices R and R. By corresponding lwith the subscriber No. Gthrough the telephone or other apparatus the operator ascertains that he desires tocommunicate with subscriber No. 12. He thereupon removes the switch-pin d12,which normallyconnects the terminal conducting-strip cl2 with the adjacent contactplate @,and inserts it between theterminal a, and the corresponding contact-plate, fm, thereby connecting` the transmitting device K with the subscriber-line 12. By operating the transmitting device K the subscriber No. 12 is then signalled. After calling subscriber No. 12 the switch-pin or connector d6 is transferred from the contact-platef to the aperture c of the plate as opposite the contactplate 1112, thereby placing the two subscribers lines in electrical connection through the transverse conductor M beneath the board. Upon ascertaining that the two subscribers are in communication, the tirst-nained connector 0112 may be removed and the two subscribers left in direct electrical connection.

The manner of connecting any calling subscriber with another whose designating number is numerically greater than that of the calling subscriber corresponds precisely to that already described. The only difference in the method ofconnecting acallingsubscriber with another subscriber whose designating number is less than his own consists in uniting the two by employing the connecting-strip of the subscriber designated by the smaller numeral, which is effected by connecting the same with the adjacent contact-plate of the subscriber designated by the greater numeral. In other words, every connection between two subscribers is made by connecting the terminal designated by the smaller numeral with the contact-plate connected with the terminal strip designated by the greater numeral.

lt will be understood from the foregoing description that for each possible combination of any two subscribers one point of connection only is provided, an organization Which mate,- rially reduces the size of the board and simplilies the construction ofthe same by cancelling one-half the usual number of apertures for receiving the switch-plugs or connectors.

l have shown and described a switch-board as adapted to twenty-tive subscribers. This particular number, however, is not material, and may be increased or diminished to any required extent, as found desirable. The electrical connections, moreover, of the annunciator device and the signal-transmitting devices may be varied at will.

I claim as my invention- The combination, substantially as hereinbefore set forth, with a series of independent liliewires, of a switch-board consisting of the series of longitudinal conductors a, of regularlydecreasing lengths, the shorter conductors being arranged end to end with the longer conduct-ors ofthe series, in such order as to render the combined lengths of each pair approximately equal, the contact-plates b, and the transverse branches M, electrically united therewith, substantially as described.

In testimony whereof I have hereunto subscribed my name this 18th day of September, A. D. 1882.

THOMAS J. PERRIN.

Witnesses:

DANIEL W. EDGEGOMB, MILLER C. EARL. 

